1. Field of the Invention
The present invention relates to a multiple air conditioner comprising a plurality of outdoor units and a plurality of indoor units, and, more particularly, to an apparatus and method of summing capacities of outdoor units of a multiple air conditioner, the apparatus and method being capable of automatically calculating the total capacity of the outdoor units to control the outdoor units.
2. Description of the Related Art
FIG. 1 is a block diagram showing an apparatus for summing capacities of outdoor units in a conventional multiple air conditioner.
As shown in FIG. 1, the conventional multiple air conditioner comprises a plurality of indoor units 10 and a plurality of outdoor units 20, which are connected to one another to perform a cooling or heating operation.
Although not shown in the drawing, an indoor heat exchanger, an indoor fan, and an expanding device are mounted in each of the indoor units 10, in the same manner as the construction of an air conditioner employing a normal cooling cycle. Similarly, a compressor, an outdoor heat exchanger, and an outdoor fan are also mounted in each of the outdoor units 20.
In the multiple air conditioner having the plurality of outdoor units as described above, the connected capacities of the plurality of indoor units 10 are restricted based on the capabilities of the compressor and the outdoor heat exchanger mounted in the each of the outdoor units.
In a main outdoor unit 21, which is one of the plurality of outdoor units 20, is mounted an outdoor unit control device 31 for controlling the operation of each of the outdoor units according to the connected capacities of the indoor units 10.
The capacity of each of the indoor units may be inputted through a dip switch mounted in each of the indoor units, or may be decided according to a program installed in an indoor unit control device. Consequently, when the indoor units 10 are operated, the total connected capacity Qin of the indoor units 10 connected to the outdoor units 20 is calculated by an indoor unit capacity summing device 33, which is also mounted in the main outdoor unit 21, through communication between the indoor units and the outdoor units, and then the calculated connected capacity Qin of indoor units 10 is recognized by the outdoor unit control device 31. Alternatively, total connected capacity Qin of the indoor units 10 may be calculated by directly inputting the capacities of the indoor units through the dip switches.
Especially, the total capacity of the plurality of outdoor units 20 is decided according to the capacities of the compressors and the outdoor heat exchangers mounted in the outdoor units 21, 22, 23, and 25. It is required that the capacities of the compressors and the outdoor heat exchanges are decided according to operation logic although the compressors are the same and the outdoor heat exchangers are also the same.
When the plurality of outdoor units 20 are connected, one of the outdoor units 20 is classified as the main outdoor unit 21, and other outdoor units 22, 23, and 25 are classified as subsidiary outdoor units. The sum of the capacities of the outdoor units 20 is directly calculated by an engineer or a user, and is then inputted to the main outdoor unit 21. Alternatively, the sum of the capacities of the outdoor units 20 may be inputted to the main outdoor unit 21 through an outdoor unit capacity input device 32, such as a dip switch, with reference to an operation manual.
Based on the sum Qout of the capacities of the outdoor units 20 inputted as described above, necessary controlling operations, such as compressor capacity calculation, sequential control mode, and control target value, are performed.
According to the method of summing the capacities of the outdoor units in the conventional multiple air conditioner, however, incorrect sum of capacities may be inputted due to errors of an engineer who initially installs the conventional multiple air conditioner. If the sum Qout of the capacities of the outdoor units 20 is incorrectly inputted, accurate control is not accomplished when the necessary controlling operations, such as compressor capacity calculation, sequential control mode, and control target value, are performed.
Even if the sum Qout of the capacities of the outdoor units 20 is correctly inputted at the beginning, the initial sum of the capacities may be changed due to incorrect manipulation or input of a user. In this case, control is not accurately performed.